Nanosized spinel oxide catalysts for CO-oxidation prepared via CoMnMgAl quaternary hydrotalcite route

Catalytic activity of the Co–Mn–Mg–Al mixed oxide spinel catalysts was examined in CO oxidation by O2. The prepared catalysts were characterized by chemical analysis (ICP), infrared spectroscopy (FTIR), thermal analysis (TG, DTG), powder X-ray diffraction (XRD), surface area measurements, and scanning electron microscopy (SEM).The calcined hydrotalcite-like precursor was composed of spinel-like Co–Mn–Mg–Al mixed oxide as the only XRD crystalline phases. The nanosized spinel oxide catalysts produced by calcination of hydrotalcites showed higher SBET than CoMn-hydrotalcite samples as calcination led to dehydroxylation and carbonate decomposition of anions in interlayer spaces. All the catalysts showed 100% CO conversion at high temperature even those calcined at 800 °C. A catalyst with Co/Mn = 4 and calcined at 500 °C showed 100% CO conversion at 160 °C. Moreover, this catalyst exhibited quite good durability without deactivation in 60 h stability test.